Liquid crystal panels for use in liquid crystal display devices such as a liquid crystal television set, for example, do not emit light by themselves and therefore need backlight units as separate lighting devices. The backlight units are well known for being mounted on a back surface of a liquid crystal panel (opposite to a display surface) and are configured to include a chassis having an opening in the surface facing the liquid crystal panel; a large number of light sources (for example, cold cathode tubes) stored as lamps in the chassis; an optical member (diffuser plate or the like) that is disposed in the opening of the chassis and efficiently emits light from the light sources toward the liquid crystal panel; and a reflection sheet that is laid in the chassis and reflects the light from the light sources toward the optical member and the liquid crystal panel. In addition, as an example of this kind of a backlight unit, there is a well-known backlight unit disclosed in Patent Document 1 shown below.
Patent Document 1: Japanese Unexamined Patent Publication No. 2006-146126